Textile fiber and method of waterproofing and strengthening the same



Patented Jan. 19, 1937 UNITED STATES TEXTILE FIBER AND METHOD OF WATER- PROOFING AND STRENGTHENING THE SIDE Joseph F. X. Harold, NewwYork, N. Y.

No Drawing.

Application February 6, 1932.

Serial No. 591,454

Claims. (Cl. 91-68) The invention relates to method of improving the wearing qualities of fabrics and endows them at the same time with resistance to water and the power of preserving for a greater time their 5 original form or dimension. It is known that the tensile strength of yarns is considerably reduced when wet and that even an excessive humidity in the air unfavorably influences it. The invention covers means of'limiting or controlling the access of water or excessive humidity to fibers and of maintaining them at water content favorable to strength.

' The waterproofing agent is elastic in character I and is in the preferred practice applied to such yarns or fabrics as have good elasticity or have the natural elasticity artificially increased before the application of the coating. It is well known that the textile fibers can be shrunk so as to render them resistant to loss of dimension in ordinary use and wear but it is also known that they can be supershrunk beyond the need of this endurance and such supershrunk fabrics while,- of course, being shrink-proof to wear or washing, are distensible but with poor elasticity so that they lose the set or dimension that the shrinkage or supershrinkage secured. Suchsupershrinkage is a disadvantage and any artificial shrinkage is a loss that does not give advantage to after-wear. If, however, the artificially shrunk fabric is treated with my elastic waterproofing agent this tendency. to distend, to approach its former dimension and to thus become permanently distorted and misshapen is counteracted. Fabrics made of fibers of naturally good elasticity often by reason of the construction or use become unequally distended or deformed because of the loss of this power of return after strain and the overpulled fiber submitted to fresh strain breaks. The automobile tire is an example of a textile-rubber composition in which rubber imparts to the combination an endurance against friction wholly impossible in the textile material free of such armament.

The art is familiar, therefore, with combinations of rubber and fiber, but in tires the rubber is the major element and the fabric is hidden. In waterproof garments the rubber is a filler of the web, forming a continuous waterproof film not designed to add strength to the textile and usually concealing any virtues in the woven de- For example in preparing cellulose fabrics for impregnation with rubber to cause them to exhibit marked extensibility when finished I may immerse the goods in a 25% to 30% solution'of caustic soda in the cold state and permit the same'to shrink freely without tension, as described by Mercer about 1850 A. D. Alternatively, after thorough washing and drying I may pass the goods into a bath of concentrated sulphuric 5 acid in the cold state for a. period of less than one minute, followed by a generous drenching with cold water to bring about in the shortest possible time the complete removal of the acid so as to minimize tendering of the goods, or the 10 acid treatment may, if desired; precede the treatment with caustic soda, this being in effect the parchmentizing method described in Matthews on Textile Fibers, fourth edition, published 1924, by J. Wiley 8: Sons, Inc., New York. See also 15 Heberleins Swiss finish in said book. See also first treatment shrinkages from 25% to 30% may be secured and by the second treatment from 10% to 12% vr'nore. Thus the fabric, according to its structure, may be reduced in length to of its 20 former dimension, or less than 40% of its former area.

For silk fibers and silk goods, especially knit wear such as stockings, I may use 95% formic acid in the cold state as the shrinking bath, a 25 period of five niinuts immersion being ample to -secure a reduction in length to about of the original. This method of super-shrinking silk is described at page 305 of Matthews. I

For woolen articles soap baths may be used, 30 these baths being rendered alkaline with soda and maintained at an elevated temperature to act as efficient shrinking liquors attended or not with fulling until super-shrinkage is reached.

In the present process the fabric or element of 35 the same is taken at its best strength and chosen elasticity and impregnated with such dispersions of latex as with proper dilutions and auxiliaries are best adapted to the animal or the vegetable fibers treated. .The rubber deposit thus devel- 40 oped in or on the fiber is well adapted by reason of its resiliency or elasticity, (its recovery from the efiect of push or pull), to aid the wearing power of the fiber, but although consisting of rubber,a highly water insoluble substance,it 5 does not make the fiber waterproof in this treatment. The rubber is deposited in a porous mass, resembling the structure of pumice, and it soaks and retains water like a rubber sponge, communicates this water to the fiber and probably 50 tends rather to keep the fiber wet for a longer period after immersion than if it were not present. If, however, the fabric bearing this porous rubber is passed through a chamber bearing the vapors of a rubber solvent, the pores collapse and the fabric 55 or fiber is coated with a continuous film, sealing the dry fiber firmly against access of water. The amount of water resident in the fiber before sealing can be varied by the degree of drying of the latex coating before fuming with solvent or by the choice of boiling point of the solvent and the freedom of entry of air to the fuming chamber. Deformation of woven and knitted fabrics, runs in knit goods; and the various strains and stresses, blows and rubs consequent upon the use 'or abuse of textile fabrics, especially garments, all are considerably reduced in their eiTect and the wearability of the fabric is much prolonged. If the process is applied to dyed goods we have the added advantage of making the colors as well as the fibers more resistant to water as in rain or laundering. Nor are rain or laundering solely to be feared as means of weakening fiber or dye. Fluids accidentallyarriving on rugs, carpets, etc., the liquors used in shampooing rugs, the eifect of damp floors especially on jute-backed fabrics, unfavorably humid storage, promoting mold, mildew, or any influences leading to bad fiber-water ratio or fiber-acid or alkali ratio all are limited or controlled by the effective sealing of the fiber at favorable ratios. Where the fabric is too unwieldly it may be sprayed with latex instead of dipped into it. Good results have been gotten even on small pieces by treating the well dried articles in a fog or mist of atomized latex and then advancing them to the second or fuming step when the resultant waterproof character was of added commercial advantage, unwaterproofed pieces treated with atomized latex may also be used without first fuming them when the porous pad-like rubber coat is of service as such. In some cases, where waterproof character is of moment, advantage is found in making the fabric as hydrophilic as possible before treatment by previously digesting it in wetting-out agents and at times the last bath or spray in this predigestion should simulate in its composition that of the latex except for the latex. That is, it should be isotonic with it, similar in pH, relative dilution and The ratio between improportion of auxiliaries. pregnation and coating is often further determined by working on quite dry goods or goods with increasing amounts of moisture or with increasing amounts of residual fluids of pretreatments isotonic or heterotonic; all these at will or choice. The virtue of the treatment as applied to fabrics rests not only on the resistance of the individual yarn or thread to wear or water but the cohesion of the fabric elements is enormously increased and where a sharply localized strain might be otherwise unsuccessfully withstood by a single thread in an untreated fabric this cohesion induced by the treatment coupled with the elasticity and the selected strengths of the fibers increases the resistance to tearing.

As an example of my process, Itake latex usually modified by slight additions of ammonia or ammonium sulfide and dilute it with ammonia water until the rubber percentage varies from one to twenty percent according to the object to as cause adhesions are applied. Yarns should be lightly treated, unless the strands are separated. The fuming box is provided with a closed steam coil and the vapor of benzene is blown in when the box is at such a temperature as to prevent the development of condensate which will cause thin spots in some places and undue accretions of rubber in others. Electric heating coils may be used safely when such solvents as chloroform are used. The goods after drying, as an alternative method, may be sprayed with benzene or chloroform.

While I have described certain methods of my treatment of textile fibers, to secure the advantages cited other coating and impregnating agents of a more or less elastic character may be employed and materials of low. elasticity may partake of only some of the advantages conse- F quent from my fumed latex treatment. Consequently, I wish to protect within the compass of the claims other impregnating materials similar in operation and character, and the novel advantages of my methods or steps therein even when short in this or that textfle of the full cooperative extent which is consequent upon my process at its perfection when applied to fabrics best adapted toit.

Having thus fully described my said invention, what I claim as new and desire to secure by Letters Patent is:

l. A process which comprises super-shrinking a fabric comprising textile fibers, treating the same with latex, drying the fabric, and subjecting it to the action of a rubber solvent for sealing the fibers.

2. An elastic textile fabric comprising supershrunk textile fibers coated with rubber latex, the rubber coating of which has been sealed with a rubber solvent.

3. An elastic textile yarn comprising supershrunk textile fibers coated with rubber, the rubber coating of which has been sealed with a rubber solvent.

4. An elastic super-shrunk textfle fiber coated with rubber, the rubber content of which has been sealed by the use of a rubber solvent.

5. An elastic super-shrunk textile fiber coated with rubber latex, the rubber content of which has been sealed by the use of a rubber solvent.

JOSEPH F. X. HAROLD. 

